; Query modem parameter using the AT commands
:MAIN
    answer

    ; each AT command is terminated by <CRLF><LINE FEED>
    $CR = chr(13)
    $NL = chr(10)
	
    ; Opens COM1 where the voice modem is expected
    ; Baud rate is set as 9600 
    ; N81 - No Parity, 8 data bits, 1 Stop bit
    if ComOpen("COM1", "9600 N81 none")
 	 
    ; Issue the AT&V command to modem   
    ComWrite("at&v")
    ComWrite($CR)
    ComWrite($NL)

    ; Get the size of data returned by modem
     $size = ComReadSize()

    ; Read the data streamed by the modem
    while $size > 0
        ; Modem is a slow device. 
        ; So wait for 2000 milliseconds for the data to arrive in the port
        $buffer = ComReadLine(2000)

        display $buffer
        log $buffer

        Sleep 1000			
        ;See for pending data size to be read
        $size = ComReadSize()
    endwhile

    ; Done. Close the port and quit
    ComClose()
  endif
	
  hangup
  goto MAIN
		
:ONSYSTEMERROR
  log $error
  hangup
  goto MAIN

• A connection is established with the serial port, COM1, where the voice modem (here) is connected. Port settings include a baudrate of 9600 bits per second having 'N' (ie., no) parity check, 8 bits constituting a byte, 1 set as the stop bit with no flow control. If the voice modem (here) is connected, then write the AT command to get the modem parameters. The size of the data to be read is found out. If the variable $size is not empty, then read each line of the data with a timeout of 2 seconds. The read data is then displayed. Then we log the read data. The serial port is checked for remaining data. If any, they are read. Then connection with the serial port is closed and control will return to the MAIN function.

See also ComOpen(), ComReadSize() ComReadLine(), ComWrite(), ComClose().